Machine for curving printing-plates.



J. S. DUNCAN. MACHINE FOR omvme PRINTING PLATES., APPLICATION FILED JULY 5,1913. 1,1 1 1,143 Patented Sept. 22, 1914.

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J. S. -D AN. MACHINE FOR 0mm RINTING PLATES. APPLICATION FILED JULY 5, 1918.

1,111,143, Patented .22, 1914.

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JOSEPH S. DUNCAN, OF CHICAGO, ILLINOIS, ASSIGNOR TO ADDRESSOGRAEH COMPANY, OF CHICAGO, ILLINOIS, A CORPURATION OF ILLINOIS.

MACHINE FOR CUBVING PRINTING-PLATES.

Specification of Letters Patent.

Patented Sept. 22, 1914:.

Application filed July 5, 1913. Serial No. 777,415.

To all whom it may concern:

Be it known that l, JosnrH S. DUNCAN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Machines for Curving Printing-Plates, of which the following is a specification.

This invention relates to machines for curving sheet metal printing plates so that they will conform to the curvature of an impression cylinder upon which they are designed to be assembled, a complete plate curved by the present machine being disclosed in my copending application Serial No. 777,411, filed July 5, 1918.

()ne of the primary objects of the present invention is the provision of a machine which will be light and simple of construction but at the same time strong and durable,

one which can be easily operated and which will be sufliciently powerful to curve a printing plate uniformly throughout its length at one operation.

Another object is the provision of a machine in which the friction between the moving parts will be very slight and which will produce a uniform pressure at each operation upon the plate being operated upon.

Other objects and many of the attendant advantages of the machine will be readily understood from the following description when considered in connection with the accompanying drawings illustrating one preferred embodiment of the invention.

Referring to the drawingsFigure 1 is a front elevation of a machine embodying my invention, showing the presser head in lowered positiong Fig. 2 is a sectional view taken on the line 22 of Fig. 1 showing the presser head in elevated position; and Fig. 3 is a fragmentary sectional view showrng the bed and the presser head in cooperatlve relation.

On the drawings reference character 5 designates a frame of suitable construction and formation adapted to support a bed 6' which may be held in position thereon by bolts 7, or other preferred means. The bed is provided on its upper face with a plurality of parallel upwardly pro ect1ng ribs 8 adapted to support a sheet metal printing plate 9 between the lines of characters formed thereon. The upper faces of the ribs are disposed on an arc so that they present a concaved face to the plate to be operated upon. i

A presser head 11 having an operating face 12 curved to conform to the curvature of the bed is carried by and preferably formed integrally with a pair of arms 13 pivoted to the frame on a shaft 14, so that the head which is normally disposed in in operative position above the bed may be lowered into operative relation with the bed as shown in Fig. 8. Both the bed and the head are made sufficiently long to operate upon a printing plate throughout its entire length. y y

A shaft 15 mounted in theframe above the bed carries an operating device in the form of a bell-crank lever comprising the upwardly extending arms 16 connected. by a handle or grip, rod 17 and a downwardly projecting arm 18 extending substantially throughout the length of the machine. The arm 18 is curved at its upper end to provide a segmental bearing surface 19 adapted to bear against the shaft 15 and at its lower end to provide a similar segmental surface 21 adapted to press against a pin or shaft 22 rotatably carried by the arm '18 and sustained by suitable eyes or bearings 23. The head 11 is provided at its ends with similar eyes or bearings 2 1 to receive a pin or shaft 25 and is also provided with a' segmental bearing surface 26 adapted to bear against the pin 25.

A bearing block 27, formed to provide segmental bearing surfaces 28 and 29 is interposed between the shafts 22 and 25 to impart thrust exerted by the shaft 22 to the shaft 25 and the shafts are prevented from separation and the block is held in place by links 30 surrounding the ends of the shafts 22 and 25. The arm 18, therefore, in conjunction with the shaft 22 and the block 27, affords a toggle connection between the operating lever and the presser head, so that when the arms 16 are swung downwardly to the right, viewing Fig. 2, the toggle will be straightened out and the head 11 will be forced into cooperative relation with the bed 6 to press the interposed printing plate into the shape shown in Fig. 3.

It will be understood that the printing plate is supported by the bed 6 only between the lines of printing characters formed thereon; consequently, the faces of the printing characters are not bent or distorted during the curving operation, the bending of the metal to effect the curvature taking place between the lines of characters. lhe printin faces of the characters are, therefore, left flat and each face is disposed tangentially to an arc concentric with the center of curvature of the plate and clear and distinct impressions will, therefore, be made by each printing character on the plate.

It will be manifest that, since the presser head is pivotally mounted and all the thrust of the operating mechanism is assumed by the segmental bearings between shafts 15, 22 and 25, the friction between the operating parts will be very slight and the machine, therefore, will be very easy to operate. By adjusting the bed 6 so that the toggle will be fully straightened when the desired pressure is exerted by the pressure head, it will be obvious that a uniform pressure will be secured at each operation; consequently, each plate operated upon will be curved the same amount.

lVhile I have shown and described a preferred embodiment of the invention, it will be manifest that various changes in the size, shape, proportion and arrangementof the various parts may be resorted to without departing from the spirit of the invention or sacrificing any of its material advantages.

I claim v A machine for curving printing plates, comprising a frame, a bed thereon provided with a plurality of ribs having their upper faces disposed on an arc and adapted to sup port a plate to be cu'rved,a shaft above said bed, a bell crank mounted on said shaft, arms pivotally mounted at one end of said frame, a head carried by said arms between the shaft and the bed and a connection be- 40 tween said head and one arm of said bell crank comprising a shaft connected with said bell crank, a shaft connected with said head, a block having segmental bearings interposed between said shafts providing a toggle adapted to force said head toward the bed upon operation of said bell crank,

and links disposed over the ends of said shafts to hold the shafts together and retain the block in position.

Witnesses:

IRA J. WILSON, M. A. KIDDIE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. v

JOSEPH s. DUNCAN. a 

